The present invention relates to locking mechanisms and more particularly to a novel locking mechanism for selectively preventing the flow of fuel from a motor vehicle tank to the motor vehicle engine and also to a novel tumbler assembly for application to various types of locks.
In recent years, theft has become an overwhelming concern of nearly everyone. One particular type of theft which has become epidemic in occurrence is auto theft. This condition particularly exists because of so-called "chop shop" activities wherein a stolen vehicle is quickly disassembled into unrecognizable components which may easily be marketed at a substantial price. It has been estimated that approximately one-third of all motorized vehicles which are stolen eventually wind up in "chop shops". The professional thief is of course the greatest contributor to this type of theft.
A second cause of such thefts is the attitude on the part of some potential thieves that auto theft is easy to accomplish and therefore, even when no pecuniary gain is made as a result of the theft, a "joy ride" may ensue. The "joy ride" type theft accounts for the remaining two-thirds of all thefts. The greatest portion of these types of thefts may be attributed to individuals who repeatedly steal and then damage motor vehicles and other properties. A relatively small portion of this two thirds is committed by professional criminals.
Many devices have been devised in the past in an effort to prevent such vehicle theft. However, repeat offenders, or those who associate with repeat offenders, are well aware of the manner in which such devices are constructed and often can defeat such devices so rapidly as to make these devices little more than a nuisance to the potential thief.
Accordingly, what is needed is an anti-theft device which will prevent the uneducated or unsophisticated thief from stealing a motor vehicle and will create such an inconvenience to a skilled and experienced thief in stealing the vehicle that such experienced thieves will be discouraged from choosing a vehicle having the anti-theft device installed.
Many anti-theft devices, including alarm systems, electronic locks and fuel line locks have been suggested in the past but each previously offered device is either to easy to defeat or prohibitively expensive to install.
For example, there are a few highly sophisticated electronic computerized systems available to the public. However, these devices are prohibitively expensive for use in any vehicle except the most expensive collector vehicles and luxury vehicles.
On the other hand, various fuel line locks have been proposed in the past which provide various amounts of inconvenience to the potential thief. Examples of such fuel line locks are disclosed in Clark, U.S. Pat. No. 4,217,925, Fontana, U.S. Pat. No. 3,792,712, Landi, U.S. Pat. No. 3,773,139, Finazzo, U.S. Pat. No. 2,881,789, Wicker, U.S. Pat. No. 1,374,621, Deadmond, U.S. Pat. No. 1,311,863 and Fuchs, U.S. Pat. No. 1,303,878. These devices are of various complexity and of various strength. However, each of these devices may be defeated relatively rapidly by a experienced car thief once he is aware of the construction of the lock.
For example, Clark provides for a locking mechanism including a rectangular housing and a tumbler assembly threaded downwardly into a threaded bore therein. A thief need only unthread the tumbler from the rectangular body and insert a screwdriver into the aperture where the tumbler previously resided to rotate the valve member into an operational position. The insertion of a cork or a thumb into the aperture to reduce the amount of air drawn into the fuel line completes the operation, and the vehicle may be driven away.
What is needed, therefore, is an anti-theft device designed with a new approach in mind. Although it is virtually impossible to provide a device which is completely tamper proof and which will prevent a determined thief having an unlimited amount of time from stealing a motor vehicle, what is needed instead is a device which will not be easily defeated with common auto theft tools and which will frustrate a potential thief by requiring an unacceptable amount of time and effort to defeat the lock. Furthermore, such an anti-theft device should inhibit theft by isolating, as much as possible, the tumbler and valve components from the interior of the motor vehicle, where they are most easily tampered with.